3.1.1.1 Atomic Structure

1/1840

Everything is made of many different atoms, which themselves are physically indivisible Democritus 400BC

Atoms are the tiny indivisible particles of elements. The atoms each have their own characteristic mass. In chemical reactions, the atoms are rearranged Experiments showed that elements could not be broken down into anything simpler Calculations of atomic masses were undergone John Dalton 1808

Atoms are not divisible but made from positive and negative matter. Negative electrons are embedded in a positive matrix Negative particles were emitted from the neutral atoms of a cathode Negative particles had negative charge and very little mass John Joseph Thompson 1897

Atoms have a very small nucleus with negative electrons orbiting it Rutherford experiment proved this Ernest Rutherford 1911

Electrons exist in shells of fixed energy around the nucleus Atoms absorb and emit electromagnetic radiation which is a result of electron movement Niels Bohr 1913

The nucleus is composed of positively charged protons and neutral neutrons which have equal mass Atomic number of an atom is equal to the number of positive charges but not it’s mass Ernest Rutherford and James Chadwick 1935

Orbital are regions where an electron is most likely to exist. Electrons can be considered to be waves. Electrons form new bonding orbital when atoms react with each other Erwin Schrodinger 1922

Charge on ion / ionic radius

3d because it is more stable

Protons and neutrons make up the nucleus Protons have a positive charge Neutrons have no charge Electrons orbit the nucleus in energy levels Electrons have a negative charge

The energy level furthest from the nucleus